Spiral patterns have been used in downhole tools as passages for cement in the context of expansion such as in hangers for liners that are set by expansion. Examples of such spiral paths for flow of displaced fluids during cementing are U.S. Pat. Nos. 6,899,181, see FIG. 9, and 7,055,597, see FIG. 7.
Another design uses grooves to reduce stress during expansion and as a location for metal displacement under inserts as the inserts engage the surrounding tubular. The stress relieving zones 885 are taught to be spiral in one alternative for the purpose of reducing expansion stress as discussed in paragraph 82 of U.S. Publication 2010/0089591.
The reality of longitudinal shrinkage during expansion of tubulars has been deployed in liner hangers to drive out slip rings 36 and 38 that are described as a cylindrical shape with a longitudinal split, a cylinder that separates into segments on expansion or a series of segments retained with a band spring in column 3 lines 52-58 of U.S. Pat. No. 7,096,938. The same description is found in the continuation U.S. Pat. No. 7,367,390.
What has yet to be developed and addressed by the present invention is a slip design that takes advantage of the longitudinal shrinkage during expansion of the hanger and configures the slip design to evenly load the surrounding tubular despite any shape irregularities it may have over an extended length of the hanger. The open nature of the slip design allows for circumferential coverage over a longer length than a longitudinally split cylinder. Beyond that a spiral design can be threaded on during assembly and provides negligible resistance to expansion. The retaining groove not only radially extends a spiral shape but also winds up gripping the slip shape more tightly as the mandrel is radially expanded and the differential longitudinal growth from mandrel expansion cocks the slip member slightly in its retaining groove to prevent shifting until the surrounding tubular wall is engaged. These and other advantages of the present invention will be more apparent to those skilled in the art from a review of the detailed description of the preferred embodiment and the associated figures while recognizing that the full scope of the invention is to be determined by the appended claims.